1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
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  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
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 16  * 2 along with this work; if not, write to the Free Software Foundation,
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 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
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 24 
 25 #ifndef SHARE_CODE_COMPILEDMETHOD_HPP
 26 #define SHARE_CODE_COMPILEDMETHOD_HPP
 27 
 28 #include "code/codeBlob.hpp"
 29 #include "code/pcDesc.hpp"
 30 #include "oops/metadata.hpp"
 31 #include "oops/method.hpp"
 32 
 33 class Dependencies;
 34 class ExceptionHandlerTable;
 35 class ImplicitExceptionTable;
 36 class AbstractCompiler;
 37 class xmlStream;
 38 class CompiledDirectCall;
 39 class NativeCallWrapper;
 40 class ScopeDesc;
 41 class CompiledIC;
 42 class MetadataClosure;
 43 
 44 // This class is used internally by nmethods, to cache
 45 // exception/pc/handler information.
 46 
 47 class ExceptionCache : public CHeapObj<mtCode> {
 48   friend class VMStructs;
 49  private:
 50   enum { cache_size = 16 };
 51   Klass*   _exception_type;
 52   address  _pc[cache_size];
 53   address  _handler[cache_size];
 54   volatile int _count;
 55   ExceptionCache* volatile _next;
 56   ExceptionCache* _purge_list_next;
 57 
 58   inline address pc_at(int index);
 59   void set_pc_at(int index, address a)      { assert(index >= 0 && index < cache_size,""); _pc[index] = a; }
 60 
 61   inline address handler_at(int index);
 62   void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; }
 63 
 64   inline int count();
 65   // increment_count is only called under lock, but there may be concurrent readers.
 66   void increment_count();
 67 
 68  public:
 69 
 70   ExceptionCache(Handle exception, address pc, address handler);
 71 
 72   Klass*    exception_type()                { return _exception_type; }
 73   ExceptionCache* next();
 74   void      set_next(ExceptionCache *ec);
 75   ExceptionCache* purge_list_next()                 { return _purge_list_next; }
 76   void      set_purge_list_next(ExceptionCache *ec) { _purge_list_next = ec; }
 77 
 78   address match(Handle exception, address pc);
 79   bool    match_exception_with_space(Handle exception) ;
 80   address test_address(address addr);
 81   bool    add_address_and_handler(address addr, address handler) ;
 82 };
 83 
 84 class nmethod;
 85 
 86 // cache pc descs found in earlier inquiries
 87 class PcDescCache {
 88   friend class VMStructs;
 89  private:
 90   enum { cache_size = 4 };
 91   // The array elements MUST be volatile! Several threads may modify
 92   // and read from the cache concurrently. find_pc_desc_internal has
 93   // returned wrong results. C++ compiler (namely xlC12) may duplicate
 94   // C++ field accesses if the elements are not volatile.
 95   typedef PcDesc* PcDescPtr;
 96   volatile PcDescPtr _pc_descs[cache_size]; // last cache_size pc_descs found
 97  public:
 98   PcDescCache() { debug_only(_pc_descs[0] = nullptr); }
 99   void    reset_to(PcDesc* initial_pc_desc);
100   PcDesc* find_pc_desc(int pc_offset, bool approximate);
101   void    add_pc_desc(PcDesc* pc_desc);
102   PcDesc* last_pc_desc() { return _pc_descs[0]; }
103 };
104 
105 class PcDescSearch {
106 private:
107   address _code_begin;
108   PcDesc* _lower;
109   PcDesc* _upper;
110 public:
111   PcDescSearch(address code, PcDesc* lower, PcDesc* upper) :
112     _code_begin(code), _lower(lower), _upper(upper)
113   {
114   }
115 
116   address code_begin() const { return _code_begin; }
117   PcDesc* scopes_pcs_begin() const { return _lower; }
118   PcDesc* scopes_pcs_end() const { return _upper; }
119 };
120 
121 class PcDescContainer {
122 private:
123   PcDescCache _pc_desc_cache;
124 public:
125   PcDescContainer() {}
126 
127   PcDesc* find_pc_desc_internal(address pc, bool approximate, const PcDescSearch& search);
128   void    reset_to(PcDesc* initial_pc_desc) { _pc_desc_cache.reset_to(initial_pc_desc); }
129 
130   PcDesc* find_pc_desc(address pc, bool approximate, const PcDescSearch& search) {
131     address base_address = search.code_begin();
132     PcDesc* desc = _pc_desc_cache.last_pc_desc();
133     if (desc != nullptr && desc->pc_offset() == pc - base_address) {
134       return desc;
135     }
136     return find_pc_desc_internal(pc, approximate, search);
137   }
138 };
139 
140 
141 class CompiledMethod : public CodeBlob {
142   friend class VMStructs;
143   friend class DeoptimizationScope;
144   void init_defaults();
145 protected:
146   enum DeoptimizationStatus : u1 {
147     not_marked,
148     deoptimize,
149     deoptimize_noupdate,
150     deoptimize_done
151   };
152 
153   volatile DeoptimizationStatus _deoptimization_status; // Used for stack deoptimization
154   // Used to track in which deoptimize handshake this method will be deoptimized.
155   uint64_t                      _deoptimization_generation;
156 
157   // set during construction
158   unsigned int _has_unsafe_access:1;         // May fault due to unsafe access.
159   unsigned int _has_method_handle_invokes:1; // Has this method MethodHandle invokes?
160   unsigned int _has_wide_vectors:1;          // Preserve wide vectors at safepoints
161   unsigned int _has_monitors:1;              // Fastpath monitor detection for continuations
162 
163   Method*   _method;
164   address _scopes_data_begin;
165   // All deoptee's will resume execution at this location described by
166   // this address.
167   address _deopt_handler_begin;
168   // All deoptee's at a MethodHandle call site will resume execution
169   // at this location described by this offset.
170   address _deopt_mh_handler_begin;
171 
172   PcDescContainer _pc_desc_container;
173   ExceptionCache * volatile _exception_cache;
174 
175   void* _gc_data;
176 
177   virtual void purge(bool free_code_cache_data, bool unregister_nmethod) = 0;
178 
179 private:
180   DeoptimizationStatus deoptimization_status() const {
181     return Atomic::load(&_deoptimization_status);
182   }
183 
184 protected:
185   CompiledMethod(Method* method, const char* name, CompilerType type, const CodeBlobLayout& layout, int frame_complete_offset, int frame_size, ImmutableOopMapSet* oop_maps, bool caller_must_gc_arguments, bool compiled);
186   CompiledMethod(Method* method, const char* name, CompilerType type, int size, int header_size, CodeBuffer* cb, int frame_complete_offset, int frame_size, OopMapSet* oop_maps, bool caller_must_gc_arguments, bool compiled);
187 
188 public:
189   // Only used by unit test.
190   CompiledMethod() {}
191 
192   template<typename T>
193   T* gc_data() const                              { return reinterpret_cast<T*>(_gc_data); }
194   template<typename T>
195   void set_gc_data(T* gc_data)                    { _gc_data = reinterpret_cast<void*>(gc_data); }
196 
197   bool  has_unsafe_access() const                 { return _has_unsafe_access; }
198   void  set_has_unsafe_access(bool z)             { _has_unsafe_access = z; }
199 
200   bool  has_monitors() const                      { return _has_monitors; }
201   void  set_has_monitors(bool z)                  { _has_monitors = z; }
202 
203   bool  has_method_handle_invokes() const         { return _has_method_handle_invokes; }
204   void  set_has_method_handle_invokes(bool z)     { _has_method_handle_invokes = z; }
205 
206   bool  has_wide_vectors() const                  { return _has_wide_vectors; }
207   void  set_has_wide_vectors(bool z)              { _has_wide_vectors = z; }
208 
209   enum : signed char { not_installed = -1, // in construction, only the owner doing the construction is
210                                            // allowed to advance state
211                        in_use        = 0,  // executable nmethod
212                        not_used      = 1,  // not entrant, but revivable
213                        not_entrant   = 2,  // marked for deoptimization but activations may still exist
214   };
215 
216   virtual bool  is_in_use() const = 0;
217   virtual int   comp_level() const = 0;
218   virtual int   compile_id() const = 0;
219 
220   virtual address verified_entry_point() const = 0;
221   virtual void log_identity(xmlStream* log) const = 0;
222   virtual void log_state_change() const = 0;
223   virtual bool make_not_used() = 0;
224   virtual bool make_not_entrant() = 0;
225   virtual bool make_entrant() = 0;
226   virtual address entry_point() const = 0;
227   virtual bool is_osr_method() const = 0;
228   virtual int osr_entry_bci() const = 0;
229   Method* method() const                          { return _method; }
230   virtual void print_pcs_on(outputStream* st) = 0;
231   bool is_native_method() const { return _method != nullptr && _method->is_native(); }
232   bool is_java_method() const { return _method != nullptr && !_method->is_native(); }
233 
234   // ScopeDesc retrieval operation
235   PcDesc* pc_desc_at(address pc)   { return find_pc_desc(pc, false); }
236   // pc_desc_near returns the first PcDesc at or after the given pc.
237   PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
238 
239   // ScopeDesc for an instruction
240   ScopeDesc* scope_desc_at(address pc);
241   ScopeDesc* scope_desc_near(address pc);
242 
243   bool is_at_poll_return(address pc);
244   bool is_at_poll_or_poll_return(address pc);
245 
246   bool  is_marked_for_deoptimization() const { return deoptimization_status() != not_marked; }
247   bool  has_been_deoptimized() const { return deoptimization_status() == deoptimize_done; }
248   void  set_deoptimized_done();
249 
250   virtual void  make_deoptimized() { assert(false, "not supported"); };
251 
252   bool update_recompile_counts() const {
253     // Update recompile counts when either the update is explicitly requested (deoptimize)
254     // or the nmethod is not marked for deoptimization at all (not_marked).
255     // The latter happens during uncommon traps when deoptimized nmethod is made not entrant.
256     DeoptimizationStatus status = deoptimization_status();
257     return status != deoptimize_noupdate && status != deoptimize_done;
258   }
259 
260   // tells whether frames described by this nmethod can be deoptimized
261   // note: native wrappers cannot be deoptimized.
262   bool can_be_deoptimized() const { return is_java_method(); }
263 
264   virtual oop oop_at(int index) const = 0;
265   virtual Metadata* metadata_at(int index) const = 0;
266 
267   address scopes_data_begin() const { return _scopes_data_begin; }
268   virtual address scopes_data_end() const = 0;
269   int scopes_data_size() const { return int(scopes_data_end() - scopes_data_begin()); }
270 
271   virtual PcDesc* scopes_pcs_begin() const = 0;
272   virtual PcDesc* scopes_pcs_end() const = 0;
273   int scopes_pcs_size() const { return int((intptr_t) scopes_pcs_end() - (intptr_t) scopes_pcs_begin()); }
274 
275   address insts_begin() const { return code_begin(); }
276   address insts_end() const { return stub_begin(); }
277   // Returns true if a given address is in the 'insts' section. The method
278   // insts_contains_inclusive() is end-inclusive.
279   bool insts_contains(address addr) const { return insts_begin() <= addr && addr < insts_end(); }
280   bool insts_contains_inclusive(address addr) const { return insts_begin() <= addr && addr <= insts_end(); }
281 
282   int insts_size() const { return int(insts_end() - insts_begin()); }
283 
284   virtual address consts_begin() const = 0;
285   virtual address consts_end() const = 0;
286   bool consts_contains(address addr) const { return consts_begin() <= addr && addr < consts_end(); }
287   int consts_size() const { return int(consts_end() - consts_begin()); }
288 
289   virtual int skipped_instructions_size() const = 0;
290 
291   virtual address stub_begin() const = 0;
292   virtual address stub_end() const = 0;
293   bool stub_contains(address addr) const { return stub_begin() <= addr && addr < stub_end(); }
294   int stub_size() const { return int(stub_end() - stub_begin()); }
295 
296   virtual address handler_table_begin() const = 0;
297   virtual address handler_table_end() const = 0;
298   bool handler_table_contains(address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
299   int handler_table_size() const { return int(handler_table_end() - handler_table_begin()); }
300 
301   virtual address exception_begin() const = 0;
302 
303   virtual address nul_chk_table_begin() const = 0;
304   virtual address nul_chk_table_end() const = 0;
305   bool nul_chk_table_contains(address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
306   int nul_chk_table_size() const { return int(nul_chk_table_end() - nul_chk_table_begin()); }
307 
308   virtual oop* oop_addr_at(int index) const = 0;
309   virtual Metadata** metadata_addr_at(int index) const = 0;
310 
311 protected:
312   // Exception cache support
313   // Note: _exception_cache may be read and cleaned concurrently.
314   ExceptionCache* exception_cache() const         { return _exception_cache; }
315   ExceptionCache* exception_cache_acquire() const;
316   void set_exception_cache(ExceptionCache *ec)    { _exception_cache = ec; }
317 
318 public:
319   address handler_for_exception_and_pc(Handle exception, address pc);
320   void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
321   void clean_exception_cache();
322 
323   void add_exception_cache_entry(ExceptionCache* new_entry);
324   ExceptionCache* exception_cache_entry_for_exception(Handle exception);
325 
326   // MethodHandle
327   bool is_method_handle_return(address return_pc);
328   address deopt_mh_handler_begin() const  { return _deopt_mh_handler_begin; }
329 
330   address deopt_handler_begin() const { return _deopt_handler_begin; }
331   address* deopt_handler_begin_addr() { return &_deopt_handler_begin; }
332   // Deopt
333   // Return true is the PC is one would expect if the frame is being deopted.
334   inline bool is_deopt_pc(address pc);
335   inline bool is_deopt_mh_entry(address pc);
336   inline bool is_deopt_entry(address pc);
337 
338   // Accessor/mutator for the original pc of a frame before a frame was deopted.
339   address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
340   void    set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
341 
342   virtual int orig_pc_offset() = 0;
343 
344 private:
345   address* orig_pc_addr(const frame* fr);
346 
347 public:
348   virtual const char* compile_kind() const = 0;
349   virtual int get_state() const = 0;
350 
351   const char* state() const;
352 
353   bool inlinecache_check_contains(address addr) const {
354     return (addr >= code_begin() && addr < verified_entry_point());
355   }
356 
357   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f);
358 
359   // implicit exceptions support
360   address continuation_for_implicit_div0_exception(address pc) { return continuation_for_implicit_exception(pc, true); }
361   address continuation_for_implicit_null_exception(address pc) { return continuation_for_implicit_exception(pc, false); }
362 
363   static address get_deopt_original_pc(const frame* fr);
364 
365   // Inline cache support for class unloading and nmethod unloading
366  private:
367   void cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all);
368 
369   address continuation_for_implicit_exception(address pc, bool for_div0_check);
370 
371  public:
372   // Serial version used by whitebox test
373   void cleanup_inline_caches_whitebox();
374 
375   virtual void clear_inline_caches();
376 
377   // Execute nmethod barrier code, as if entering through nmethod call.
378   void run_nmethod_entry_barrier();
379 
380   void verify_oop_relocations();
381 
382   bool has_evol_metadata();
383 
384   // Fast breakpoint support. Tells if this compiled method is
385   // dependent on the given method. Returns true if this nmethod
386   // corresponds to the given method as well.
387   virtual bool is_dependent_on_method(Method* dependee) = 0;
388 
389   virtual address call_instruction_address(address pc) const = 0;
390 
391   Method* attached_method(address call_pc);
392   Method* attached_method_before_pc(address pc);
393 
394   virtual void metadata_do(MetadataClosure* f) = 0;
395 
396   // GC support
397  protected:
398   address oops_reloc_begin() const;
399 
400  public:
401   // GC unloading support
402   // Cleans unloaded klasses and unloaded nmethods in inline caches
403 
404   virtual bool is_unloading() = 0;
405 
406   void unload_nmethod_caches(bool class_unloading_occurred);
407   virtual void do_unloading(bool unloading_occurred) = 0;
408 
409 private:
410   PcDesc* find_pc_desc(address pc, bool approximate) {
411     return _pc_desc_container.find_pc_desc(pc, approximate, PcDescSearch(code_begin(), scopes_pcs_begin(), scopes_pcs_end()));
412   }
413 };
414 
415 #endif // SHARE_CODE_COMPILEDMETHOD_HPP